Indium gallium aluminum nitride (InxGayAl1-x-yN, 0<=x<=1, 0<=y<=1) is one of the optimal materials for manufacturing short-wavelength light-emitting devices. Recently, many new light-emitting devices have been manufactured using InGaAlN materials, such as blue, green, ultraviolet, and white light-emitting diodes (LEDs). The existing technologies indicate that the majority of the InGaAlN light-emitting products are manufactured on sapphire substrates. Currently, these technologies are publicly available. For example, Japanese patent JP2737053 discloses a method for fabricating GaN light-emitting devices on a sapphire substrate. Because sapphire is an insulator, it is required that the two electrodes of an InGaAlN light-emitting device manufactured on a sapphire substrate be positioned on the same side of the chip. As a result, the chip fabrication process is more complex, with increased packaging difficulty. In addition, the product yield is reduced. Consequently, the device reliability is lessened and the product costs are increased. Furthermore, the thermal conductivity of sapphire is low. If high-power devices are desired, heat dissipation remains an issue. One solution is to use SiC substrate to fabricate GaN materials based on the fact that SiC is electrically conductive and has a high thermal conductivity. Hence, technically, using SiC substrates can solve the aforementioned problems. U.S. Pat. No. 5,686,738 discloses a method for fabricating InGaAlN light-emitting devices on SiC substrates. However, SiC substrates are very expensive, which results in high costs if they are used in manufacturing InGaAlN materials. Therefore, from a production-cost point of view, SiC substrates are not suitable for high-volume production. Another solution is to fabricate InGaAlN materials on silicon substrates. Since silicon is a well-tested semiconductor material with low costs and high thermal conductivity, and silicon-processing techniques are mature, using silicon substrate in manufacturing InGaAlN light-emitting devices can not only facilitate a vertical-electrode device structure, but also significantly reduces the costs. However, since the band gap of silicon is fairly narrow and silicon exhibits considerable absorption of visible light, InGaAlN light-emitting devices directly fabricated on a silicon substrate exhibit low luminescence efficiency due to absorption of light by the substrate. Another solution available in the existing technologies is to bond a conductive substrate to the InGaAlN material fabricated on a sapphire substrate. The sapphire substrate is subsequently removed, and electrodes can then be placed on both sides of the substrate. Nevertheless, since sapphire is very hard and resistant to acid or base corrosion, it is very difficult to remove a sapphire substrate. Although laser-lift-off technologies can be used to remove sapphire substrates, the product yield and manufacturing efficiency remain low. The laser-lift-off process can also cause certain damage to the InGaAlN material. Therefore, it is difficult to apply this method to volume production.